Mechanisms for ejecting objects from a tire tread

ABSTRACT

Apparatus for ejecting objects from a tire tread include, in particular embodiments, a pair of adjacent ground-engaging elements, each element including a ground-engaging contact surface; a groove separating the pair of ground-engaging elements, the groove having a base and a pair of opposing sidewalls spaced apart by a groove width; a sipe having a particular size, and located in communication with a portion of the groove extending between the pair of ground-engaging elements; and, an ejector associated with the sipe, the ejector comprising a projection that extends within the groove.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to tread patterns for tires, and morespecifically, to tread patterns having mechanisms for ejecting stonesand other objects from the tire tread.

2. Description of the Related Art

It is generally known that tires include a tread portion for engaging aground surface. The tread portion may include a tread pattern forgenerating traction between the ground surface and the tire. Treadpatterns may include circumferential grooves, lateral (transverse)grooves, and other types of voids, which may be used independently orconjunctively to form traction edges. Further, such voids may alsoabsorb and/or displace water, snow, mud, sand, and the like to improvetire traction. However, such voids may also accept stones and otherobjects, which may become lodged within the tire tread. These objectsmay be detrimental to the performance and safety of a host tire, as theobjects may reduce tire traction, and/or cause tire imbalance, wear,abrasions, and punctures.

Accordingly, when an object becomes lodged in a tire tread pattern, itmay be difficult for the object to dislodge without further assistance.If known mechanisms cannot prevent objects from becoming lodged, it maybe desirous to provide a mechanism that can dislodge objects withouthaving to stop a vehicle to personally remove a lodged object. Such amechanism may also be helpful when a vehicle operator is unaware of anyobject within the tread, which may give rise to a safety issueunbeknownst to the vehicle operator.

SUMMARY OF THE INVENTION

Particular embodiments of the present invention include an apparatus forejecting objects from a tire tread portion. Particular embodiments ofthe present invention include a tire tread having a length extending ina longitudinal direction, a width extending in a lateral direction, anda depth extending in a vertical direction, the tire tread including: apair of adjacent ground-engaging elements, each element including aground-engaging contact surface; a groove separating the pair ofground-engaging elements, the groove having a base and a pair ofopposing sidewalls spaced apart by a groove width; a sipe having aparticular size, and located in communication with a portion of thegroove extending between the pair of ground-engaging elements; and, anejector associated with the sipe, the ejector comprising a projectionthat extends within the groove. In particular embodiments, the sipe islocated along one of the sidewalls, the one of the sidewalls beingopposite the sidewall containing the ejector. In particular embodiments,the sipe is located along an ejector.

Particular embodiments of the present invention may also include a tiretread having a length extending in a longitudinal direction, a widthextending in a lateral direction, and a depth extending in a verticaldirection, the tire tread comprising: a pair of adjacent ground-engagingelements, each element including a ground-engaging contact surface; agroove separating the pair of ground-engaging elements, the groovehaving a base and a pair of opposing sidewalls spaced apart by a groovewidth; an ejector comprising a projection extending within the groovefrom one of the groove sidewalls, and including a leading side, atrailing side, and a lateral side extending between the leading andtrialing sides; and, a first sipe having a particular size and locatedin communication with the groove, wherein the first sipe is locatedadjacent either the leading side or the trailing side of the ejector,along the same sidewall containing the ejector. Particular embodimentsmay also provide the first sipe being located adjacent either theleading side or the trailing side of the ejector, along the samesidewall containing the ejector. Particular embodiments may also includea second sipe extending from the same sidewall as the ejector, thesecond sipe having a particular size and located in communication withthe groove, wherein the first sipe is located adjacent to one of theleading or trailing sides of the ejector, and the second sipe is locatedadjacent to the other of the leading or trailing side of the ejector.Particular embodiments may also provide the first sipe being locatedadjacent the lateral side of the ejector, along a sidewall that opposesthe sidewall containing the ejector.

The foregoing and other objects, features and advantages of theinvention will be apparent from the following more detailed descriptionsof particular embodiments of the invention, as illustrated in theaccompanying drawing wherein like reference numbers represent like partsof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of an exemplary tire tread pattern, according to anembodiment of the invention.

FIG. 2 is a top view of an exemplary tread pattern portion showing aparticular sipe-ejector arrangement along a groove, in accordance withan embodiment of the invention.

FIG. 3 is a side view of a groove sidewall of the exemplary treadpattern shown in FIG. 2.

FIG. 4 is a top view of an exemplary tread pattern portion showing aparticular sipe-ejector arrangement along a groove, in accordance withan embodiment of the invention.

FIG. 5 is a side view of a groove sidewall of the exemplary treadpattern groove shown in FIG. 4.

FIG. 6 is a side view of a groove sidewall of the exemplary treadpattern shown in FIG. 2, showing the tire tread exiting a tirefootprint, in accordance with an embodiment of the invention.

FIG. 7 is a side view of a groove sidewall of the exemplary treadpattern shown in FIG. 4, showing the tire tread exiting a tirefootprint, in accordance with an embodiment of the invention.

FIG. 8 includes related side views of each groove sidewall of theexemplary tread pattern shown in FIG. 2, the related side views showingthe relative motion between each side as the tread exits the tirefootprint, in accordance with an embodiment of the present invention.

FIG. 9 is perspective view of an exemplary ejector, in accordance withan embodiment of the invention.

FIG. 10 is perspective view of an exemplary ejector, in accordance withan embodiment of the invention.

FIG. 11 is perspective view of an exemplary ejector, in accordance withan embodiment of the invention.

FIG. 12 is perspective view of an exemplary ejector, in accordance withan embodiment of the invention.

FIG. 13 is perspective view of an ejector, in accordance with anembodiment of the invention.

FIG. 14 is a side view of a groove sidewall of an exemplary treadpattern showing a particular sipe-ejector arrangement along a groove, inaccordance with an embodiment of the invention.

FIG. 15 is a side view of a groove sidewall of an exemplary treadpattern showing a particular sipe-ejector arrangement along a groove, inaccordance with an embodiment of the invention.

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

Particular embodiments of the present invention include apparatus forejecting or dislodging objects from a tire tread portion. In suchembodiments, tread portions or treads that include such ejectingapparatus may be attached to a tire, or may exist separately from atire, such as when, for example, the tread is used to retread a tire.

With reference to FIG. 1, tire tread portion 10 generally includes alength, a width, and a depth. The length extends in a longitudinaldirection (D_(C)), which is also the circumferential direction of thetire when the tread is located on the tire. The tread width extends in alateral direction (D_(L)) perpendicular to the tread centerline (CL),while the tread depth extends in a vertical direction. Exemplaryembodiments of the tire tread portions and the object ejecting apparatusare described herein.

As shown exemplary in FIG. 1, tread portion 10 may include one or moreground-engaging elements, such as ribs 12 or lugs 14. Ground-engagingelements contact the ground within a tire footprint or contact patch.Each rib 12 generally extends about the circumference of a tire 10 inone or more directions, and is generally bounded by one or morelongitudinal grooves 20. Each rib 12 may remain substantiallycontinuous, or may comprise a plurality of lugs 14. Lugs 14 generallyinclude a ground-engaging surface, and are generally defined by one ormore longitudinal grooves 20 and one or more lateral grooves 21. It iscontemplated that lugs 14 may exist without the existence of any rib 12,where each such lug 14 may be arbitrarily or randomly located alongtread 10 so not to be arranged within a rib 12.

With continued reference to FIG. 1, an exemplary tread portion 10includes one or more projections referred to herein as ejectors 30. Anejector 30 generally extends within a groove and may interact with astone or other object that is lodged, or is otherwise located within,groove 20. Each groove 20, 21 generally includes opposing groove walls22 a, 22 b and a groove bottom 24. Ejectors 30 may extend within alongitudinal groove 20 or a lateral groove 21, either from a groovesidewall 22 or a groove bottom 24.

Longitudinal groove 20 generally has a depth (i.e., height), and mayextend in a particular path, which may be linear or non-linear. Forexample, the path may be linear, arcuate, or zig-zag, as exemplarilyshown in FIG. 1. Further, groove 20 may extend along a path thatultimately extends around the circumference of a tire, or may extend alimited distance, such as between one or more ground-engaging treadelements, such as ribs 12 or lugs 14. Groove 20 may extend in adirection parallel to tread centerline (CL), or at any angle relativethereto. Grooves 20 generally have a width (W_(G)), such that opposinggroove walls 22 a, 22 b do not collapse inwardly across width (W_(G)) tocontact each other when traveling within a tire footprint. In particularembodiments, groove widths (W_(G)) may comprise between 2 and 20millimeters (mm), while tread depths may extend between 20 and 24 mm.However, it is contemplated that larger and smaller groove widths(W_(G)) and depths may exist, as various tire sizes and designs mayexist for various purposes. Contrary to grooves 20, sipes 50 are narrowslits or elongated voids that generally remain closed or collapseinwardly at least when traveling through a tire footprint. Grooves 20,21 provide tread void for displacing water, snow, and the like from thefootprint, while decreasing traction surface area. Sipes 50 providelittle change in void, but provide other benefits, such as reducingtread stiffness and tread heat, and increasing traction by way ofproviding additional traction edges.

As shown in FIGS. 1-5, sipes 50 may generally extend downward from atread contact surface 16 of ribs 12 or lugs 14, and may vary in size andshape. For example, sipes 50 may extend through any depth of tread 10,to achieve a desired height (H_(s)). FIGS. 3 and 5 exemplarily showsipes 50 extending partially through the depth or height of aground-engaging element. FIG. 14 exemplarily shows sipes 50 that fullyextend through the depth or height of a ground-engaging element. Sipes50 may also extend fully or partially across the width of any rib 12 orlug 14, and may travel in any direction relative to the tire lateraldirection (D_(L)), which includes in particular embodiments extendingsubstantially in the tire lateral direction (D_(L)) as exemplarily shownin FIG. 1. As each sipe 50 extends in any direction, each sipe 50 mayfollow any desired path, which includes any linear, arcuate, or zig-zagpath. FIGS. 1, 2, and 4 exemplarily show sipes 50 extending in alaterally extending zig-zag path, while FIGS. 3 and 5 show sipes 50extending in a downward zig-zag path. FIG. 14 shows a linear downwardpath. Sipes 50 may include a large void 52 located near or at aninternal end of the sipe 50, such as is shown in an exemplary embodimentin FIG. 14. Void 52 may comprise any shape and size, and may bepositioned or arranged in any relation to sipe 50. It is generallyunderstood that any sipe design or construction known to one havingordinary skill in the art may be used in accordance with this invention.

With general reference to FIGS. 2-5, each ejector 30 has a leading side32 and/or a trailing side 34, whether extending from a groove sidewall22 or from a groove bottom 24, and is defined by a height (H_(E)), awidth (W_(E)), and a length (L_(E)). The dimensional size of eachejector 30 may vary as each tire varies is size and purpose. Inparticular embodiments, an ejector 30 may have a width (W_(E)) thatextends between 2 and 10 mm and a length (L_(E)) that extends between 5and 60 mm. It is contemplated that an ejector 30 may extend any distanceinto a groove 20. In particular embodiments, the ejector 30 width(W_(E)) comprises up to approximately 50% of the groove width (W_(G)),although more is contemplated. In other embodiments, the ejector 30width (W_(E)) comprises between 10% and 30% of the groove width (W_(G)).

An ejector 30 may also have one or more lateral sides 36 that face agroove sidewall 22. Any and all sides 32, 34, 36 of ejector 30 mayextend in any direction. In particular embodiments, one or more sides ofejector 30 may be inclined relative to the groove bottom 24, asexemplarily shown in FIGS. 2-5, 9-13, which may generally provide anejector 30 having a cross-section that narrows with increasing ejectorheight (H_(E)). These inclined sides may assist in ejecting objects byengagingly directing an object outwardly from groove 20.

With continued reference to FIGS. 2-5, particular embodiments of ejector30 may include a lateral side 36 having one or more ridges 38, which mayextend in any direction along, or relative to, lateral side 36. Inparticular embodiments, ridges 38 may extend any distance along a heightof ejector 30, that is, in some radial (vertical) direction outward agroove 20, 21. It is also contemplated that ridges 38 may extendlongitudinally or laterally along any side 32, 34, 36. With specificreference to FIG. 12, it is contemplated that each of the two separatedforms shown may operate as a single ejector 30, or may be usedindividually to function as a single ridge ejector 30. A ridge 38 mayassist in the ejection of an object by providing less surface area forengaging the object, which concentrates the forces transmitted byejector 30 to better manipulate, twist, and force the object from groove20.

Each ejector 30 generally includes one or more leading surfaces 37, eachof which generally face the direction of tire rotation. With specificreference to FIGS. 3 and 5, exemplary embodiments of ejector 30 includeleading surfaces 37 that are located on leading side 32 and alonglateral side 36. Leading surfaces 37 may assist in ejecting objects, asthe leading surfaces 37 may transmit ejecting forces against anycontacting object, so to propel or push the object forward and/or out ofthe tread as the ejector 30 rotates out from the footprint.

Particular embodiments of ejector 30 may also include a top side 40and/or a bottom side 41. Top side 40 may function to deter stones orother objects from entering any groove 20, 21. It is contemplated thatejector bottom side 41 may extend to the groove bottom 24, asexemplarily shown in FIGS. 2-5, or be located above, or offset, from thegroove bottom 24, as exemplarily shown FIG. 15.

It is understood that ejectors 30 may comprise any desired shape orform, or combinations thereof. For example, ejectors 30 may form acuboid, a pyramid, a tetrahedron, or may be cylinder-like orsphere-like, or otherwise form any arbitrary shape. FIGS. 8-13 provideexemplary embodiments of these and other forms of ejectors 30. Withreference to FIG. 12, it is considered that each shape or ejector 30 maybe partitioned, or associated with a neighboring shape or ejector 30 tooperate as a single ejector 30. It is understood that surfaces and/orshapes may be merged, as exemplarily shown in FIG. 9, where the surfacesassociated with leading and trailing sides 32, 34 merge with lateralside 36. Surfaces may be concave or convex, as exemplarily shown inFIGS. 9-10. Sides 32, 34, and/or 36 may extend perpendicularly relativeto the groove bottom 24 or may extend radially at any desired bias, suchthat a surface thereof faces a direction outward groove 20, 21. Thisorientation may provide an ejection mechanism, as any ejecting contactthat such surface may have with an object would direct the objectoutward from groove. This may also improve the wear, blistering, andtear properties of such ejectors 30.

In operation, a sipe 50 may generate object-ejecting movement along agroove sidewall 22 when entering or exiting a tire footprint. Morespecifically, sipe 50 may generate such movement by angularly orrotationally deflecting (i.e., opening) prior to entering, or subsequentto exiting, the tire footprint, which is exemplary shown in FIGS. 6-8.FIGS. 6-7 exemplarily show a sipe 50 generating movement along a groovesidewall as the tread exits a tire footprint. This movement may bedescribed by the increase in sipe 50 spacing ES, as it moves from thefootprint (ES₀) to the post-footprint (i.e., exiting) area (ES₁).

Movement generated along one groove sidewall 22 may be transformed intorelative movement along the groove 20 between opposing groove sidewalls22 a, 22 b. FIG. 8 exemplarily describes relative movement betweenopposing groove sidewalls 22 a, 22 b. Specifically, FIG. 8 uses thesipe-ejector arrangement of FIG. 6 to exemplify and describe relativemovement along a groove 20, which is applicable to other sipe-ejectorarrangements, including those described herein. In FIG. 8, Δ₀ identifiesthe footprint spacing between a sipe 50 and an ejector 30 along sidewall22 a, which is relationally projected upon opposing sidewall 22 b.Further, Δ₁ references the same spacing upon exiting the tire footprint,in an area of increased angular deflection. It is apparent that Δ₁ isgreater than Δ₀, which evidences a relative movement of the associatedrib 12 or lug 14 along sidewall 22 a. In particular, the associatedejector 30 moves along sidewall 22 a in the direction of tire rotationas the associated sipe 50 opens. This movement also provides an increasein relative movement between sidewalls 22 a and 22 b, which becomesapparent when projecting the deflections Δ₀ and Δ₁ onto sidewall 22 b.It follows that other sipe-ejector arrangements may provide relativemovement between groove sidewalls 22 a, 22 b, provided such arrangementprovides sipes that are not directly located opposite a sipe 50, or asimilarly sized and shaped sipe 50.

To facilitate ejection of stones and other objects from tread 10,ejectors 30 operate in conjunction with one or more sipes 50 in variousarrangements to generate an ejecting motion along groove 20 and/or 21.Along a groove 20, an ejector 30 is located relative to one or moreassociated sipes 50, each of which may extend from within ejector 30 asexemplary shown in FIGS. 4-5, and/or may be located adjacent to anejector 30 as exemplarily shown in FIGS. 2-3. When a sipe 50 is locatedwithin an ejector 30, it is contemplated that such sipe 50 may belocated anywhere along the length (L_(E)) of ejector 30, which may becentrally located as shown in FIGS. 4-5. In particular embodiments, anadjacent sipe 50 may be located along the groove sidewall 22 thatcontains the associated ejector 30, as exemplarily shown in FIGS. 2-3,where the associated sipe 50 may be located adjacent a leading ortrailing side 32, 34 of the ejector 30. Embodiments may also provide anadjacent sipe 50 that is located across a groove 20 along an opposinggroove sidewall 22, which is also exemplarily represented in FIGS. 2-3.

With regard to the first adjacent sipe-ejector arrangement discussedabove, in which adjacently associated sipes and ejectors are containedalong a single sidewall 22 (the “co-existing sipe-ejector sidewallarrangement”), the sipes 50 may be located any distance from a side 32,34 of ejector 30. Deflection of ejector 30 may increase when theassociated sipe 50 is more closely located to a side 32, 34. In oneembodiment, a sipe 50 is located a zero distance from a side 32, 34. Inanother embodiment, a sipe 50 is located approximately 1 mm from a side32, 34. In yet another embodiment, an ejector 30 has a length of 7millimeters (mm), and the adjacently associated sipe 50 is located 1.5mm from a side 32, 34, which approximately provides a 1:5 ratio inassociating sipe offset to ejector length. In other embodiments, a sipe50 is adjacently located on each side 32, 34 of ejector 30, as shown inFIGS. 2-3, which may provide increased deflection over a single sipearrangement. Accordingly, when providing multiple ejectors 30 along asidewall 22, where each ejector 30 has sipes 50 adjacently located oneach side 32, 34, as exemplarily shown in FIGS. 2-3, each ejector 30 mayhave associated one or more sipes 50 that (1) are not associated orshared with an adjacent ejector 30 (i.e., each ejector 30 has one ormore independently associated sipes 50), and/or (2) are shared with anadjacent ejector 30, where each such sipe 50 is located between theadjacent ejectors 30 as exemplarily shown in FIGS. 2-3. Ejectingcapabilities may also increase when including the co-existingsipe-ejector sidewall arrangement on both sidewalls 22 a, 22 b, whichmay be arranged in staggered relation as represented in FIGS. 2-3. Suchstaggered arrangement may include a standard spacing or a non-standardspacing, such as when attempting to reduce any noise generated by thetread during tire operation.

In the second adjacently associated sipe-ejector arrangement discussedabove, which provides a sipe 50 adjacently located along a sidewall 22opposite an ejector 30 (the “opposing sidewall sipe-ejectorarrangement”). In this embodiment, one or more sipes 50 may be locateddirectly opposite a portion of an ejector 30 in the tread lateraldirection (D_(L)), or any distance there from even though withincreasing distance the sipe-ejector association may become lesseffective in generating object-ejecting movement. This sipe-ejectorarrangement may be repeated along a groove 20 in a staggered relation(i.e., all ejectors are located along a single sidewall 22). Thissipe-ejector arrangement may also be repeated in an alternatingstaggered relation (i.e., ejectors and sipes of different sipe-ejectorarrangements are located on the same sidewall 22), which is representedin FIGS. 2-3.

When facilitating ejection motion with any associated sipe 50 andejector 30 arrangement discussed above, it is contemplated that eachsipe 50 vertically overlap the associated ejector. In other words, theheights of an ejector 30 and an associated sipe 50 are overlapped whenportions of both extend through a single transverse plane, where theplane extends both in the lateral (D_(L)) and longitudinal (D_(C))directions. This overlap is identified as (Ov) in FIGS. 3, 5, 14, and15. It is contemplated that any overlap is useful in generating ejectingmotion, although effectiveness generally increases with increasingoverlap (Ov). In one embodiment, 50% of an ejector 30 is overlapped byan associated sipe 50. In another embodiment, 100% of the ejector 30 isoverlapped, as shown exemplarily in FIG. 15. FIGS. 3, 5, and 14 show anoverlap of less than 100% but greater than 50%.

In the arrangement discussed above, it is contemplated that each sipe 50may not be located opposite another sipe 50 along groove 20 to generallyprovide relative motion, or shearing, between opposing groove sidewalls22 a, 22 b. Therefore, it may be desirous to maintain any opposing sipes50 in a spaced apart or staggered arrangement. However, it iscontemplated that ejecting motion may be provided when a sipe 50 opposesanother sipe 50 if the opposing sipes 50 are different in size and/orshape or provide a different overlap (Ov) with its associated ejector30. This may still facilitate ejection motion as the different sipes 50may provide different deflections or movement between opposing groovesidewalls 22 a, 22 b.

While this invention has been described with reference to particularembodiments thereof, it shall be understood that such description is byway of illustration and not by way of limitation. Accordingly, the scopeand content of the invention are to be defined only by the terms of theappended claims.

What is claimed is:
 1. A tire tread having a length extending in alongitudinal direction, a width extending in a lateral direction, and adepth extending in a vertical direction, the tire tread comprising: apair of adjacent ground-engaging elements, each element including aground-engaging contact surface; a groove separating the pair ofground-engaging elements, the groove having a groove bottom and a pairof opposing sidewalls spaced apart by a groove width, the groove havinga length and a groove depth extending perpendicular to the groove lengthfrom the ground-engaging contact surface to the groove bottom; aplurality of sipes arranged along the groove length, each sipe having aparticular size, and located in communication with a portion of thegroove extending between the pair of ground-engaging elements, saidplurality of sipes including a first arrangement of sipes spaced alongone of the pair of opposing sidewalls, and a second arrangement of sipesspaced along the other of the pair of opposing sidewalls; a pluralityejectors spaced along the groove length, each ejector having a top side,a bottom side and a height extending from the top side to an ejectorbottom side, the ejector comprising a projection that extends into thegroove from one of the groove sidewalls, wherein each ejector includestwo ridges protruding from the lateral side and extending into thegroove and in a direction of the groove depth, the two ridges beingspaced apart in the direction of the groove length to form a recessedportion between the two ridges; wherein the first arrangement of sipesis staggered relative to the second arrangement of sipes in a directionof the groove length; said plurality of ejectors and said plurality ofsipes being configured to provide relative movement between the pair ofopposing sidewalls for ejecting objects from the tire tread, whereinsaid each of the plurality of sipes extends downwardly from theground-engaging contact surface of a ground-engaging element at leastpartially past the top surface of each of said plurality of ejectors andextends substantially across the width of a ground-engaging element. 2.The tire tread as recited in claim 1, wherein each of the plurality ofsipes is located within one of the plurality of the ejectors.
 3. Thetire tread as recited in claim 2, wherein each of the plurality of sipesextends completely across the width of said ground-engaging element. 4.The tire tread as recited in claim 2, where each of the pluralityejectors forms a narrowed portion of the groove width.
 5. The tire treadas recited in claim 1, wherein each of the plurality of sipes is locatedalong one of the sidewalls adjacent one of the plurality of ejectors. 6.The tire tread as recited in claim 5, wherein the ejector bottom side isoffset from the groove bottom and each of the plurality of sipes extendscompletely downwardly past said ejector bottom side within the groove.7. The tire tread as recited in claim 5, wherein each of the pluralityof sipes located on one of the pair of sidewalls is located opposite oneof the plurality of ejectors arranged on the other of the pair ofsidewalls across the width of the groove.
 8. The tire tread as recitedin claim 5, where each of the plurality ejectors forms a narrowedportion of the groove width.
 9. The tire tread as recited in claim 1,wherein each ejector includes a cross-section and a height extendingaway from the groove bottom, where the cross-section narrows as theejector extends from a portion closest to the groove bottom.
 10. Thetire tread as recited in claim 1, wherein each ground-engaging elementof the pair of elements is a rib or a lug.
 11. The tire tread as recitedin claim 1, wherein each of the plurality of sipes has a height suchthat the height of each of the plurality of sipes and the height of eachof the plurality of ejectors extends through a transverse planeextending the lateral and longitudinal directions of the tread.
 12. Thetire tread as recited in claim 1, each ejector having a height definedas the distance between the top side of the ejector and an ejectorbottom side, wherein the ejector bottom side is offset from the groovebottom.
 13. The tire tread as recited in claim 1, wherein one or more ofthe plurality of the ejectors is associated with two or more of theplurality of sipes.
 14. The tire tread as recited in claim 1, where eachof the plurality ejectors forms a narrowed portion of the groove width.15. The tire tread as recited in claim 1, where each of the plurality ofsipes are arranged within one of the plurality of ejectors between thepair of ridges.